Definition & Facts for Diverticular Disease

In this section:

What is diverticulosis?

Diverticulosis is a condition that occurs when small pouches, or sacs, form and push outward through weak spots in the wall of your colon. These pouches are most common in the lower part of your colon, called the sigmoid colon. One pouch is called a diverticulum. Multiple pouches are called diverticula. Most people with diverticulosis do not have symptoms or problems.

When diverticulosis does cause symptoms or problems, doctors call this diverticular disease. For some people, diverticulosis causes symptoms such as changes in bowel movement patterns or pain in the abdomen. Diverticulosis may also cause problems such as diverticular bleeding and diverticulitis.

Diverticular bleeding

Diverticular bleeding occurs when a small blood vessel within the wall of a pouch, or diverticulum, bursts.


Diverticulitis occurs when you have diverticulosis and one or a few of the pouches in the wall of your colon become inflamed. Diverticulitis can lead to serious complications.

Illustration of the colon of a person with diverticulosis and diverticulitis. Includes labels for diverticulosis, diverticulitis, diverticula, inflammation, bleeding, colon, and intestines.
Diverticulosis and diverticulitis

What are the complications of diverticulitis?

Diverticulitis can come on suddenly and cause other problems, such as the following:


An abscess is a painful, swollen, infected, and pus-filled area just outside your colon wall that may make you ill with nausea, vomiting, fever, and severe tenderness in your abdomen.


A perforation is a small tear or hole in a pouch in your colon.


Peritonitis is inflammation or infection of the lining of your abdomen. Pus and stool that leak through a perforation can cause peritonitis.


A fistula is an abnormal passage, or tunnel, between two organs or between an organ and the outside of your body. The most common types of fistula with diverticulitis occur between the colon and the bladder or between the colon and the vagina in women.

Intestinal obstruction

An intestinal obstruction is a partial or total blockage of the movement of food or stool through your intestines.

How common are diverticulosis and diverticulitis?

Diverticulosis is quite common, especially as people age. Research suggests that about 35 percent of U.S. adults age 50 years or younger have diverticulosis, while about 58 percent of those older than age 60 have diverticulosis.1 Most people with diverticulosis will never develop symptoms or problems.2

Experts used to think that 10 to 25 percent of people with diverticulosis would develop diverticulitis. However, newer research suggests that the percentage who develop diverticulitis may be much lower—less than 5 percent.2

In the United States, about 200,000 people are hospitalized for diverticulitis each year. About 70,000 people are hospitalized for diverticular bleeding each year.3

Who is more likely to have diverticulosis and diverticulitis?

People are more likely to develop diverticulosis and diverticulitis as they age.

Among people ages 50 and older, women are more likely than men to develop diverticulitis. However, among people younger than age 50, men are more likely to develop diverticulitis.3


Last Reviewed May 2016

This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health. The NIDDK translates and disseminates research findings to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by the NIDDK is carefully reviewed by NIDDK scientists and other experts.